Funded Projects

Medication-based treatment for opioid use disorder OUD aids in reducing mortality, opioid withdrawal, intake and opioid-seeking behaviors, however there is a clear need to increase the armamentarium of therapeutics for OUD. The ?non-classical? NOcicePtin receptor (NOPr) binds the endogenous neuropeptide nociceptin/orphanin FQ (N/OFQ) and is a promising target based on the evidence for its function in the regulation of the rewarding and motivational effects of opioids and alcohol. This study plans to assess the ability of the novel and selective NOPr antagonist BTRX-246040 to block oxycodone intake without abuse liability, and to suppress oxycodone withdrawal and relapse-like behaviors in rats. The study will also determine Drug Metabolism and Pharmacokinetics interactions (DMPK) between oxycodone and BTRX-246040 and brain penetrability in male and female rats. If successful, these preclinical studies will be followed by a Phase 1 clinical trial in non-treatment seeking OUD participants. These investigations will advance the prospects of validating a novel medication for OUD.

Kappa opioid receptors (KOR) are expressed in brain areas that control reward, motivation, and anxiety. Upon opioid drug withdrawal and abstinence, dysregulated KOR signaling can result in aversive physical and affective states that are a major driver of relapse. Preclinical data have demonstrated that antagonism of KOR can reduce the physical symptoms of opioid withdrawal. Currently, the alpha 2-adrenergic agonist lofexidine is the only approved therapy for the mitigation of the physical symptoms of opioid withdrawal but it is only modestly effective and can have significant unwanted side effects. Cerevel Therapeutics has identified a novel selective KOR antagonist, CVL-354, with unique properties and good preclinical safety margins. This project will assess this drug in early human safety/pharmacokinetics and occupancy studies. Future studies will then be able to assess efficacy of this drug in acute opioid withdrawal.

Over 2 million Americans have an Opioid Use Disorder (OUD) and the risks associated with misuse of opioids have prompted a public health crisis. There are three effective FDA-approved drugs for medication assisted treatment (MAT) of OUD. However, while MAT can reduce overall OUD related mortality by as much as fifty percent, relapse and treatment discontinuation are common within the first 5 to 12 weeks of MAT. As longer treatment retention is correlated with better long-term outcomes, the development of an adjunctive medication to alleviate key psychiatric symptoms associated with treatment failure would address an important unmet need. This study seeks to evaluate the safety and efficacy of brexpiprazole as adjunctive treatment to buprenorphine/naloxone in OUD. If successful, this study could enhance the effectiveness of OUD treatments by extending the duration of treatment, thereby reducing the likelihood for relapse and overdose.

The excruciating multiday experience of opioid withdrawal syndrome (OWS), is exacerbated by the opioid antagonist drugs naloxone and naltrexone. This industry-academia collaboration will explore the potential of the glutamate AMPA receptor antagonist Tezampanel (TZP). Animal studies have shown reduced hyperactivity in brain circuits involved in OWS, without relying on direct stimulation or antagonism of the opioid system ,and has already been delivered to over 500 human subjects and found to be safe for a potential migraine indication. This proposal will build up the evidence needed to apply for and conduct open label and blinded placebo-controlled human trials of TZP safety and efficacy for OWS. If successful, this project will allow planning for a pivotal registration trial for TZP for OWS, and as a transitional treatment to long-term recovery on naltrexone and help us stem the tide of the opioid crisis.

Responding to urgent calls for non-opioid treatment, this research group has been evaluating the therapeutic potential of cannabidiol (CBD), a non-intoxicating cannabinoid, for the treatment of some clinical aspects of opioid use disorder (OUD). Preclinical animal studies show that CBD decreases cue-induced heroin-seeking behavior during drug abstinence, associated with incubation of craving. Clinical work has also shown that CBD was safe in combination with a potent opioid agonist to address a potential relapse condition and decreased craving and anxiety associated with heroin cues in abstinent individuals with heroin use disorder. Building on this foundation, the researchers will investigate an oral CBD powered by a novel patented technology (leveraging the kinetics of long-chain fatty acid absorption) in a gelcap delivery system that improves bioavailability, reduces the incidence of gastrointestinal side effects, reduces first pass metabolism, and enhances onset time. This study could lead to the development of a non-opioid, non-intoxicating FDA-approved medication to reduce opioid craving and relapse and restore global functioning in individuals with OUD.

To address the need for novel therapeutics for opioid use disorder (OUD), this research group identified ghrelin as an endogenous regulator of the mesocorticostriatal circuit, which contributes to the enhanced motivational attributes of addictive drugs and drug-associated cues. Ghrelin binds to the growth hormone secretagogue receptor 1? (GHS1?R) to transduce several physiological and behavioral processes, including the reward-related effects of opioid agonists. Systemic administration of a GHS1?R antagonist/inverse agonist dose-dependently attenuated self-administration of the addictive opioid analgesic oxycodone as well as oxycodone-seeking. This project proposes to employ a suite of validated rodent OUD models to define the preclinical profile for PF5190457, a selective GHS1?R antagonist/inverse agonist. PF5190457’s abuse liability, ability to suppress withdrawal and relapse-like behaviors, drug metabolism and pharmacokinetics, and brain penetrability in rats will be assessed. Phase 1 clinical studies in non–treatment seeking OUD participants will follow to assess the safety and tolerability of PF5190457.

There is a need to develop a mu-opioid receptor (MOR) treatment with enhanced therapeutic effects and reduced undesirable effects. Recently, several highly selective and potent MOR modulators have been identified as novel leads for opioid use disorder treatment. They all showed more promising pharmacological profiles compared to other known drugs in this category. The current proposal will focus on further development of these leads for preclinical IND-enabling studies and dynamic drug discovery and development pipeline construction. This project plans to further validate therapeutic profiles of the current leads with self-administration and pharmacokinetic studies and expand the small-molecule library to build a dynamic drug discovery and development pipeline. Preclinical IND-enabling studies on the identified lead(s) will be conducted, and in vivo pharmacokinetics and pharmacodynamics profiles of the new hits will be compared with current leads to define the next generation of lead compound(s).

There is a need for pharmacologic treatment options for opioid use disorder (OUD) that do not pose addiction liability and do not require complete withdrawal from opioids prior to treatment. Nonclinical studies support a role for the orexin system in drug seeking; compounds that selectively block signaling at the orexin-1 receptor (OX1R) reduce drug use. C4X3256, a non-opioid, highly selective OX1R antagonist, has a long residence time at the OX1R along with reduced intravenous self-administration and cue-induced reinstatement in animal models of nicotine addiction, suggesting it could be an addiction treatment. Proposed studies will move C4X3256 from preclinical development through Phase I testing in subjects with OUD. The clinical, preclinical, and supporting pharmaceutical development studies proposed will allow C4X3256 to move to Phase II studies.

Current opioid overdose treatment requires administration of naloxone by first responders, which requires timely identification of the overdose, the need for a rescue injection, and immediate availability of the medication. The development of a fail-safe treatment that would provide a life-saving dose of naloxone without the need for intervention by another party could significantly reduce mortality. The researchers aim to develop a new medical device comprising an implantable, closed-loop system that senses the presence of an opioid overdose, automatically administers a life-saving bolus injection of naloxone, and simultaneously alerts first responders.

Extended-release naltrexone (XR-NTX) reduces overdose risk; however, transitioning to XR-NTX requires detoxification, which is a major hurdle. Non-opioid detoxification with an alpha-2 adrenergic receptor agonist, such as lofexidine, may shorten detoxification time, but it does not reduce the subjective effects of withdrawal. Pregabalin potentiates the activity of glutamic acid decarboxylase, inhibits calcium influx and release of excitatory neurotransmitters, raises GABA levels, and is approved for neuropathic pain, for fibromyalgia, and as an adjunctive therapy for adults with partial onset seizures. The study will test whether pregabalin can be combined with lofexidine to better reduce the subjective effects of opioid withdrawal than lofexidine alone and increase the proportion of patients that transition to XR-NTX. Such a dosing combination could lower the detoxification hurdle for patients who are interested in antagonist treatment or who are in settings where it is unavailable or difficult to access.

Opioid use disorder (OUD) and opioid overdose (OD) are major health issues. Breathing can be restored after OD by naloxone, but its short half-life can require multiple administrations to reverse OD, and OD symptoms may return after initial reversal if illicit opioids are still present after the effects of naloxone have worn off. Additionally, while the standard treatment of OUD with buprenorphine and methadone reduces relapse and mortality, access and adoption are limited by dosage forms, metabolic liabilities, and potential for misuse and diversion. This study seeks to develop chemically novel, potent mu-opioid receptor (MOR) antagonists and low- and mid-efficacy partial agonists. Current lead counts can outcompete opioid overdoses in preclinical models with a longer half-life, a key naloxone liability for treating OD. The potent, low-efficacy partial agonists add a low opioid tone, diminishing the aversive effects of pure antagonists. These, and the mid-efficacy partial agonists, are leads to maintenance therapeutics for OUD.

Naltrexone (NTX) has been proven as an important, safe, and effective therapy in helping patients overcome opioid addition and in preventing overdose. Unfortunately, the therapeutic potential of NTX has been blunted by poor adherence. To combat this issue, a system must be developed to deliver NTX for longer durations than are currently available with a more patient-friendly format. The goal of this research is to optimize and scale up our laboratory PLGA-based microparticle formulations of NTX delivery (either 2 months or 7–10 days) and bridge it to a Phase 1 clinical trial. This innovation will result in a more patient-friendly format consisting of less painful injections and improved release kinetics. PLGA-based drug delivery systems have been used successfully in a number of small-molecule products and are the most widely utilized and studied biocompatible polymer systems in controlled release. Thus, the regulatory and development hurdles with the FDA will be lower than with other novel excipients or technologies. The significance of this research and product development is that the final outcome of this project will ultimately provide a new, readily viable, essential tool to help patients overcome opioid dependence.